On 14/08/2016 06:16, harry wrote:
On Sunday, 14 August 2016 01:42:30 UTC+1, Fredxxx wrote:
On 13/08/2016 17:56, harry wrote:
On Saturday, 13 August 2016 08:18:46 UTC+1, charles wrote:
In article ,
harry wrote:
On Friday, 12 August 2016 10:24:48 UTC+1, Dave Plowman (News) wrote:
In article ,
Clive George wrote:
Yup. Although the bottle type tended to give a brighter light in the
days when I cycled. But a friction drive is horribly inefficient.

Sturmey hub vs other bottle? Yes, the sturmey hub wasn't very
powerful - the wheel turns quite slowly, so the magnets required
weren't available (or at least not at a sane price) back then. The
modern hub dynamos give rather more.

That certainly makes sense. Modern low voltage DC motors have also been
improved out of all recognition by better magnets.

There is no such thing as a DC motor.
I've told you before.

does that mean that those hand held fans run from a battery need an
inverter to work? I think not. And I'm sure the starter motot in my car
runs on DC.


No it runs on AC.
The "commutator and brushes" are a mechanical inverter.

driven by DC and hence called a DC motor.
https://en.wikipedia.org/wiki/DC_motor

You can deny "A DC motor is any of a class of electrical machines that
converts direct current electrical power into mechanical power" but to
do so only emphasises your ignorance.

These are expensive and wear out so these days it's replaced with electronics to turn DC to AC where ever possible.

Care to give examples of car starter motors that don't use brushes?

They need brushes and a commutator to convert the DC to AC.
Are you so thick you can't Google this?
https://en.wikipedia.org/wiki/Commutator_(electric)

So you are starting to admit that you supply DC to a DC motor.

Or are you the sort to suggest you should supply a DC motor with AC?